The present invention relates to an image processing method and apparatus, and more particularly, to an image processing method and apparatus having a function where data received from a host computer is overlaid on a pre-registered standardized form to generate new image data.
Recently, outline fonts have been widely employed as a font in order to generate character pattern corresponding to character code data.
Main features of the outline font include easiness of character processing and fineness of the generated character pattern. However, there is a drawback that the time required to generate a character pattern employing the outline font is longer than that taken in a method employing a dotted pattern font. In order to reduce the processing time, a once-generated character pattern as a dot-pattern is registered in a cache memory for the next usage. When the same code is inputted, the registered character pattern is read out of the cache memory. In this manner, time for generating the dot character pattern is saved.
The above method controls available spaces in the cache memory in accordance with access frequencies of the registered character patterns. More specifically, when the cache memory becomes full, one character pattern of the lowest access frequency is deleted to create an available space for registration of a new character pattern.
However, in a case where an inputted data has to be overlaid on pre-registered form data and the overlaid image is outputted, the above-mentioned conventional approach has dealt with all the data without consideration of the type of data such as an ordinary character data or character data for a form. In many cases, when the cache memory becomes full, character data for a form might be deleted from the memory first because appearance frequency of the form character data is different from that of an ordinary character data. Thereafter, a deleted form character pattern must be read into the cache memory again upon form output. For example, a page printer employing the outline font rereads a once-deleted form character data into its cache memory and generates a dot patten, which takes much more time in dot pattern formation at every page, increasing processing time by final image formation.